Molecules 2011, 16
5217
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389.2/3.46; IR (KBr, cm−1): 3141(NH), 1705 (C=O); H-NMR (DMSO-d6), δ: 13.76 (1H, bs, NH),
7.78 (1H, s, CH), 7.53–7.44 (1H, m, H4´), 7.37 (1H, dd, J = 7.7 Hz, J = 1.7 Hz, H6´), 7.14 (1H, d,
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J = 7.7 Hz, H3´), 7.08 (1H, t, J = 7.7 Hz, H5´), 3.88 (3H, s, OCH3); C-NMR (DMSO-d6), δ: 196.3,
169.6, 158.3, 133.2, 129.9, 126.9, 125.5, 121.5, 121.4, 112.2, 56.0.
(5Z)-5-(3-Methoxybenzylidene)-2-thioxo-1,3-thiazolidin-4-one (4b). Yellow crystalline compound;
Yield 81%; Mp 236–237 °C (232 °C [29]); Anal. Calcd. for C11H9NO2S2 (251.32): C 52.57%,
H 3.61%, N 5.57%, S 25.52%; found: C 52.73%, H 5.43%, N 5.65%, S 25.87%; UV (nm), λmax/log ε:
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379.6/3.41; IR (KBr, cm−1): 3151 (NH), 1698 (C=O); H-NMR (DMSO-d6), δ: 13.82 (1H, bs, NH),
7.60 (1H, s, CH), 7.44 (1H, t, J = 8.1 Hz, H5´), 7.16–7.03 (3H, m, H2´, H4´, H6´), 3.79 (3H, s, OCH3);
13C-NMR (DMSO-d6), δ: 195.8, 169.5, 159.9, 134.5, 131.8, 130.7, 126.0, 122.6, 116.9, 115.8, 55.5.
(5Z)-5-(4-Methoxybenzylidene)-2-thioxo-1,3-thiazolidin-4-one (4c). Yellow crystalline compound;
Yield 90%; Mp 260–261 °C (261–262 °C [30]); Anal. Calcd. for C11H9NO2S2 (251.32): C 52.57%,
H 3.61%, N 5.57%, S 25.52%; found: C 52.25%, H 3.60%, N 5.75%, S. 27.94%; UV (nm), λmax/log ε:
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385.6/3.48; IR (KBr, cm−1): 3137 (NH), 1687 (C=O); H-NMR (DMSO-d6), δ: 13.72 (1H, bs, NH),
7.59 (1H, s, CH), 7.58–7.50 (2H, m, AA´, BB´, H2´, H6´), 7.13–7.05 (2H, m, AA´, BB´, H3´, H5´),
3.82 (3H, s, OCH3); 13C-NMR (DMSO-d6), δ: 195.7, 169.6, 161.5, 132.9, 132.1, 125.7, 122.4,
115.3, 55.8.
(5Z)-5-(4-Hydroxy-3-methoxybenzylidene)-2-thioxo-1,3-thiazolidin-4-one (5). Yellow crystalline
compound; Yield 75%; Mp 233–234 °C (227–228 °C [31]); Anal. Calcd. for C11H9NO3S2 (267.32):
C 49.42%, H 3.39%, N 5.24%, S 23.99%; found: C 49.46%, H 3.17%, N 5.24%, S 22.56%; UV (nm),
λmax/log ε: 406.1/3.33; IR (KBr, cm−1): 3340 (OH), 3269 (NH), 1714 (C=O); 1H-NMR (DMSO-d6), δ:
10.09 (1H, bs, OH), 7.56 (1H, s, CH), 7.14 (1H, d, J = 2.1, H2), 7.07 (1H, dd, J = 8.4 and 2.1, H6),
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6.92 (1H, d, J = 8.4, H5), 3.82 (3H, s, OCH3); C-NMR (DMSO-d6), δ: 195.7, 169.7, 150.2, 148.3,
133.0, 125.3, 124.6, 121.3, 116.6, 114.5, 55.8.
(5Z)-5-[(4-Dimethylamino)benzylidene]-2-thioxo-1,3-thiazolidin-4-one (6). Orange crystalline
compound; Yield 90%; Mp 283–286 °C (283–284 °C [30]); Anal. Calcd. for C12H12N2OS2 (264.37):
C 54.52%, H 4.58%, N 10.60%, S 24.26%; found: C 54.38%, H 4.75%, N 10.68%, S 22.70%;
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UV (nm), λmax/log ε: 463.0/3.39; IR (KBr, cm−1): 3138 (NH), 1683 (C=O); H-NMR (DMSO-d6), δ:
13.55 (1H, bs, NH), 7.49 (1H, s, CH), 7.45–7.36 (2H, m, AA´, BB´, H2´, H6´), 6.84–6.76 (2H, m,
AA´, BB´, H3´, H5´), 3.01 (6H, s, NCH3); 13C-NMR (DMSO-d6), δ: 195.2, 169.6, 151.9, 133.5, 133.1,
120.0, 117.5, 112.4, 39.8.
(5Z)-5-(2-Nitrobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (7a). Yellow crystalline compound; Yield
68%; Mp 190–195 °C (204–205 °C [32]); Anal. Calcd. for C10H6N2O3S2 (266.30): C 45.10%,
H 2.27%, N 10.52%, S 24.08%; found: C 43.78%, H 1.53%, N 10.14%, S 26.31%; UV (nm),
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λmax/log ε: 360.1/3.43; IR (KBr, cm−1): 3098 (NH), 1735 (C=O); H-NMR (DMSO-d6), δ: 13.93 (1H,
bs, NH), 8.19 (1H, d, J = 8.2 Hz, H3´), 7.92–7.84 (1H, m, H5´), 7.86 (1H, s, CH), 7.76–7.66 (2H, m,